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A new approach to measuring transepithelial potentials in the bovine lens reveals a chloride‐dependent component
Author(s) -
Zhang JJ,
Jacob TJ
Publication year - 1994
Publication title -
experimental physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.925
H-Index - 101
eISSN - 1469-445X
pISSN - 0958-0670
DOI - 10.1113/expphysiol.1994.sp003804
Subject(s) - transepithelial potential difference , furosemide , amiloride , ouabain , lens (geology) , epithelium , biophysics , chemistry , membrane potential , anatomy , endocrinology , ion transporter , biology , medicine , biochemistry , sodium , pathology , membrane , paleontology , organic chemistry
A new approach was used to measure anterior and posterior potentials and resistances of the bovine lens. Segments of the anterior, central and posterior lens were studied by mounting a disc of tissue from either the front or the back of the lens in a double chamber. At 35 degrees C the isolated anterior epithelial preparation exhibited a high potential of 9 mV and a low resistance of 279 omega cm2. The lens epithelium can therefore be classified as a ‘leaky’ or low resistance epithelium. Amiloride, benzamil and furosemide (frusemide) all reduced the anterior transepithelial potential and increased the resistance, amphotericin B (aqueous side) abolished the potential, whereas SITS (4‐acetamido‐4'‐isothiocyanatostilbene‐2,2'‐disulphonic acid) had no effect. The posterior lens preparation was found to have a ‘transepithelial’ of ‐4 mV. This potential and a proportion of the anterior potential were not sensitive to ouabain, amiloride, furosemide, Na+ removal or raised K+, but were abolished by lowering [Cl‐] and reduced by the Cl‐ channel blocker NPPB. We conclude that chloride plays a significant role in the maintenance of transepithelial potentials at both the anterior and posterior surfaces of the lens.